A new update is now live in Heroes of the Storm, adding a new hero to Blizzard's MOBA along with competitive mode changes that lead to the launch of season one, a new unranked draft mode, and more. This post has complete patch notes, this article has details on season 1 rewards and the seasonal rollover, and here is where to find details on Medivh, the new hero this brings to the Nexus. Here's more on Medivh:

Medivh is a powerful ranged Specialist who wields arcane powers to manipulate the battlefield to the benefit of his team—and to the detriment of his enemies. With the ability to create portals for his team and become an invulnerable Raven, players will soon learn that it’s great to have this Archmage on their side. Read on for more detailed info on some of his talents and Hero synergies.